Soil microbial respiration in arctic soil does not acclimate to temperature.
Citation
Philip A Wookey, Iain P Hartley, David W Hopkins, Mark H Garnett, and Martin Sommerkorn, Soil microbial respiration in arctic soil does not acclimate to temperature.: .
Summary
Warming-induced release of CO2 from the large carbon (C) stores in arctic soils could accelerate climate change. However, declines in the response of soil respiration to warming in long-term experiments suggest that microbial activity acclimates to temperature, greatly reducing the potential for enhanced C losses. As reduced respiration rates with time could be equally caused by substrate depletion, evidence for thermal acclimation remains controversial. To overcome this problem, we carried out a cooling experiment with soils from arctic Sweden. If acclimation causes the reduction in soil respiration observed after experimental warming, then it should subsequently lead to an increase in respiration rates after cooling. We demonstrate [...]
Summary
Warming-induced release of CO2 from the large carbon (C) stores in
arctic soils could accelerate climate change. However, declines in the
response of soil respiration to warming in long-term experiments suggest
that microbial activity acclimates to temperature, greatly reducing the
potential for enhanced C losses. As reduced respiration rates with time
could be equally caused by substrate depletion, evidence for thermal
acclimation remains controversial. To overcome this problem, we carried
out a cooling experiment with soils from arctic Sweden. If acclimation
causes the reduction in soil respiration observed after experimental
warming, then it should subsequently lead to an increase in respiration
rates after cooling. We demonstrate that thermal acclimation did not
occur following cooling. Rather, during the 90 days after cooling, a
further reduction in the soil respiration rate was observed, which was
only reversed by extended re-exposure to warmer temperatures. We
conclude that over the time scale of a few weeks to months,
warming-induced changes in the microbial community in arctic soils will
amplify the instantaneous increase in the rates of CO2 production and
thus enhance C losses potentially accelerating the rate of 21st century
climate change. Published in Ecology letters, volume 11, issue 10, on
pages 1092 - 100, in 2008.
